The invention disclosed herein relates generally to an apparatus for separating sheets from a stack and, more particularly, to an apparatus and method for identifying a collation and separating the entire collation from a stack.
It is known to be desirable in the paper handling art to provide paper handling apparatus with mechanisms known as accumulators, which accumulate a sequence of sheets being processed by the apparatus to form a stack, or accumulation, for further processing. For example, a sequence of sheets might be fed to a printer for printing of predetermined information, and the output of the printer fed in seriatim to an accumulator where a predetermined number of sheets in the sequence would be accumulated, and the resulting accumulation passed on for further processing, such as folding and insertion into an envelope.
An input subsystem associated with any insertion system typically includes separation of sheets from a primary source such as, e.g., through sheet feeding, bursting, or cutting, and then transport of those sheets at very high-speed into an accumulating device. As the cycle rates of these systems have been required to increase, so have the velocities, accelerations, and decelerations of each sheet that is processed. Prior art involves the separation and linear transport of each sheet into an accumulator, then after the specified number of sheets has been assembled into a collation, the collation is removed from the accumulator in a linear fashion at high-speed so that the collations can be assembled as quickly as possible.
Thus, one of the problems of the prior art is that it requires high-speed manipulations to accumulate a collation. Another problem of the prior art is that high-speed manipulation can be costly. Another problem of the prior art is that high-speed manipulation can be mechanically complex. Still another problem of the prior art is that high-speed manipulation can be noisy. Yet another problem of the prior art is that high-speed manipulation can require unnatural paper motions.
The present invention does not require high-speed manipulation of individual sheets to accumulate collations. Instead of processing the sheets seritatim at very high velocities, the individual sheets are identified as part of a collation and separated as a collation while they are still in their original, sheet-feeding stack. That is, rather than separating each sheet from the stack and re-accumulating the sheets for collation processing, collations are removed from the supply stack and processed as a whole. This reduces the need for high-speed transports and accumulating techniques. Although the example cited above refers to a typical sheet feeding application, this technique can also be applied to high-speed cutting and bursting applications in which cut/burst sheets are accumulated in a stack for subsequent feeding.
This invention overcomes the disadvantages of the prior art by providing a method and apparatus for identification and separation of an entire collation from a supply stack. This is in contrast to conventional processing techniques that entail separation of singular sheets from a supply stack, and their transport and accumulation at high linear velocities. Thus, the present invention affords for more efficient and higher reliability collation processing. The present invention is directed to, in a general aspect, an apparatus and method for separating an entire collation of individual sheets from a supply stack for downstream processing. The apparatus generally comprises: a supply stack tray for containing the supply stack while the collations in the supply stack are being separated; a separator device positioned adjacent to the supply stack tray for separating a corner of each sheet of the collation from the supply stack; a deflector positioned adjacent to an edge of the collation for deflecting the collation from the supply stack after the collation has been separated by the separator; and a gripper device positioned in a plane proximate to the first sheet in the collation for gripping the entire collation after the collation has been deflected from the supply stack and for moving the entire collation downstream for processing. The method for separating a collation of individual sheets from a supply stack comprises, generally, the steps of separating a corner of each of the individual sheets in the collation from the supply stack; deflecting the collation from the supply stack; and gripping the entire collation and moving the entire collation from the supply stack for downstream processing.
The undesirable aspects of conventional sheet processing and accumulating techniques are readily apparent when associated sheet velocities, accelerations, and decelerations are considered. The present inventions provides a way to reduce associated paper motions, e.g., velocities, accelerations, and decelerations, enhance system reliability and cost aspects, as well as minimize acoustic noise. By eliminating the need to separate and transport each sheet seriatim into an accumulating station (at velocities which could exceed 300 inches per second (ips) for high-speed inserting applications) advantages can be gained.
Thus, an advantage of the present invention is that it reduces the paper manipulations and velocities required to generate a collation. Another advantage of the present invention is that it provides a collation accumulating process that can enhance the performance, cycle rate, cost, and overall reliability of down stream processing devices such as statement generation and processing devices of an inserter. Another advantage of the present invention is that it can replace conventional methods associated with high-speed sheet processing and associated accumulation techniques. Other advantages of the invention will be obvious and will in part be apparent in part from the specification. The aforementioned advantages are illustrative of the advantages of the various embodiments of the present invention.